Diagnosis and indications for the extraction of third molars - The SECIB clinical practice guideline.

BACKGROUND: The removal of third molars (3Ms) is the most frequent surgical procedure in the field of Oral Surgery. As a result, the Spanish Society of Oral Surgery (SECIB) aims to create a Clinical Practice Guideline (CPG) that offers evidence-based recommendations for optimal clinical practice. Specifically, the CPG will focus on providing guidance regarding the indications and criteria for clinical and radiological diagnosis of patients with 3Ms. MATERIAL AND METHODS: This CPG was developed by the SECIB, following the methodological guidelines described in the methodological manual for the "Development of Clinical Practice Guidelines in the National Health System". Several PICO questions related to the diagnosis and indications for the extraction of 3Ms were formulated. The leading experts carried out the evaluation of the evidence and the formulation of specific recommendations. RESULTS: A total of 17 PICO questions were evaluated, addressing the indications, prognosis, diagnosis, and cost-benefit relationship of 3M extraction. CONCLUSIONS: The present Clinical Practice Guideline provides evidence-based recommendations on the diagnosis and indications for 3M extraction. These evidence-based recommendations can assist healthcare professionals and the general population in making informed decisions regarding the management of 3Ms.

Clinical practice guideline of the spanish society of oral surgery for oral surgery in patients with coagulation disorders.

BACKGROUND: The number of patients treated with coagulation disorders, and more specifically with anticoagulant therapy, has increased worldwide in recent years due to increased life expectancy in developed countries. The protocols for managing this type of patient in oral surgery has varied over recent years, especially after the appearance of new direct-acting oral anticoagulants (DOACs). The assessment of risk of bleeding in this type of patient when undergoing a surgical procedure continues to be a controversial issue for patients, dentists and general practitioners. The objective of this document is to offer recommendations, based on evidence, for decision making for patients with coagulopathies who require dental surgical intervention. MATERIAL AND METHODS: Based on the indications of the "Preparation of Clinical Practice guidelines in the National Health System. Methodological manual", we gathered a group of experts who agreed on 15 PICO questions based on managing patients with coagulation disorders in dental surgical procedures, such as fitting of implants or dental extractions. RESULTS: The 15 PICO questions were answered based on the available evidence, being limited in most cases due to the lack of a control group. Two of the PICO questions were answered by the experts with a grade C recommendation, while the rest were answered with grade D. CONCLUSIONS: The results of this review highlight the need to undertake well designed clinical trials with control groups and with a representative sample size.

Antibiotic prophylaxis in the prevention of dry socket and surgical site infection after lower third molar extraction: a network meta-analysis.

Clinicians frequently prescribe systemic antibiotics after lower third molar extractions to prevent complications such as surgical site infections and dry socket. A systematic review of randomised clinical trials was conducted to compare the risk of dry socket and surgical site infection after the removal of lower third molars with different prophylactic antibiotics. The occurrence of any antibiotic-related adverse event was also analysed. A pairwise and network meta-analysis was performed to establish direct and indirect comparisons of each outcome variable. Sixteen articles involving 2158 patients (2428 lower third molars) were included, and the following antibiotics were analysed: amoxicillin (with and without clavulanic acid), metronidazole, azithromycin, and clindamycin. Pooled results favoured the use of antibiotics to reduce dry socket and surgical site infection after the removal of a lower third molar, with a number needed to treat of 25 and 18, respectively. Although antibiotic prophylaxis was found to significantly reduce the risk of dry socket and surgical site infection in patients undergoing lower third molar extraction, the number of patients needed to treat was high. Thus, clinicians should evaluate the need to prescribe antibiotics taking into consideration the patient's systemic status and the individual risk of developing a postoperative infection.

Early complications and quality of life in patients with immediately loaded implant-supported maxillary partial rehabilitations: A prospective cohort study.

BACKGROUND: Immediate loading of dental implants is considered an excellent option to reestablish function and aesthetics in a short period of time, thereby reducing the psychological impact of edentulism. The aim of this study was to describe the incidence of complications in immediately loaded implant-supported single or partial maxillary provisional rehabilitations; to assess changes in patient quality of life (QoL); to evaluate patient overall satisfaction; and to determine whether the occurrence of complications affects these outcomes. MATERIAL AND METHODS: Patients requiring partial rehabilitation with implants in the maxilla were included in a prospective cohort study. In all cases, implant-based restoration with an immediate loading protocol was indicated. A provisional restoration was placed within 72 hours after implant placement. Patient QoL was measured at the first appointment and just before placing the final restoration, using two validated questionnaires. All mechanical and biological complications occurring up until placement of the final restoration were documented. A descriptive and bivariate analysis of the data was performed. RESULTS: Thirty-five patients with 40 prostheses supported by 60 implants were analyzed. Three implant failures were observed, yielding a 95% survival rate. Five provisional prosthesis fractures and two prosthetic screw loosenings were recorded in four patients. A significant reduction in OHIP-14 score was observed. Likewise, significant differences were found in the results of the QoLFAST-10, with a mean difference in score of 7.3 between the initial and final evaluation. CONCLUSIONS: Patients receiving immediately loaded implant-supported single or partial maxillary provisional rehabilitations seem to have a low risk of developing early mechanical (13.3%) or biological complications (5%). These patients appear to experience significant improvement in QoL and report excellent overall satisfaction with the treatment received - though the occurrence of complications seems to affect these outcomes.

Predictors of surgical difficulty in upper third molar removal: a prospective cohort study.

BACKGROUND: Upper third molar (U3M) removal is a common surgical procedure. The aims of this study were to assess the patient-specific, radiological and surgical factors related to the difficulty of U3M removal, and to determine the incidence of intraoperative and postoperative complications. MATERIAL AND METHODS: A prospective cohort study was carried out in adult patients undergoing U3M removal. Operative time, surgeon-reported difficulty and the Parant classification were used to assess extraction difficulty. Clinical, radiological and surgical factors were recorded to determine their relationship with surgical difficulty. A descriptive, bivariate and multivariate statistical analysis was carried out. RESULTS: A total of 250 patients were included. The mean operative time was 10.4 (±12.3) minutes, mean surgeon-reported difficulty was 3.2/10 (±2.3). The multivariate analysis showed greater impaction against the second molar and greater soft tissue and bony impaction to significantly increase operative time and surgeon-perceived difficulty. Additionally, surgeon experience was related to perceived difficulty. The overall incidence of intraoperative complications was 0.8%, and no postoperative events were recorded. CONCLUSIONS: Upper third molars in close relation with the roots of the adjacent second molar and with soft tissue and bony impaction are significantly more difficult to extract. Perceived difficulty was related to surgeon experience. This procedure appears to produce few intra- and postoperative complications.

Valorization of wipe wastes for the synthesis of microporous carbons and their application in CO2 capture, gas separation and H2-storage.

Wipe wastes have been used as a cellulosic source to synthesize biochars. Prior to the synthesis of the adsorbents by the pyrolysis of wipes wastes, this waste was treated to remove the pathogenic agents. Then, the wipe wastes were pyrolyzed between 500 and 900 °C to obtain biochars, whose microporosity increased proportionally to the pyrolysis temperature, achieving a maximum CO2-adsorption uptake of 2.53 mmol/g at a pressure of 760 mm of Hg and 25 °C for the biochar pyrolized at 900 °C. The synthesized biochars are also highly selective towards CO2-adsorption in CO2/N2 or CO2/H2 mixtures. Hence, these adsorbents have shown a great potential to be used in flue gas treatment and H2-purification processes. Biochar treatment with KOH further improves microporosity due to chemical activation although the addition of a large amount of KOH leads to excessive microporosity causing a collapse in the pore structure and decreasing CO2-adsorption capacity.

Patient-centered outcomes after surgical treatment of peri-implantitis: a prospective clinical study.

BACKGROUND: Peri-implantitis is an inflammatory process affecting soft and hard tissues surrounding dental implants, causing progressive marginal bone loss. Peri-implant surgery is the treatment of choice. However, evidence about its impact on patients' quality of life (QoL) is limited. This study aimed to assess pain and QoL in the first seven post-operative days and measure patient satisfaction at the end of this period. MATERIAL AND METHODS: A prospective cohort study was conducted in patients with peri-implantitis. Patients reported pain on a visual analogue scale (VAS) ranging from 0 to 100mm every day during the first week after surgery. They then completed the OHIP-14sp questionnaire. A descriptive and inferential data analysis was used to assess the effect of surgical approach (resective, regenerative or combined), gender and working status on pain, satisfaction and QoL. RESULTS: Forty-one patients (93,2%) completed the daily pain VAS; scores ranged from 0 to 95 mm. Gender, occupation, or type of surgery had no significant effect upon its evolution. The mean total OHIP-14sp score was 16.7 (range = 5 to 33), indicating low to moderate deterioration in perceived oral health. Postoperative OHRQoL was significantly higher in working patients (mean difference (MD): 3.94; P = 0.042), and with the regenerative (MD: 6.34; P = 0.044) or the combined approach (MD: 5.41; P = 0.027). CONCLUSIONS: Considering the limitations of this study, postoperative pain was mild to moderate and decreased after the third day. Surgical treatment of peri-implantitis has an impact on QoL, especially when augmentation procedures are involved. This impact is higher in working patients.

Comparison of two different lingual flap advancement techniques and vascular structure identification: a human cadaver study.

BACKGROUND: One of the most frequent complications in guided bone regeneration (GBR) is wound dehiscence, which compromises treatment outcomes. Thus, primary tension-free suture is essential to avoid wound dehiscence. The purpose of this study was to compare the extension of 2 different mandibular flaps in human cadaveric specimens, and to measure the size of the supraperiosteal blood vessels. MATERIAL AND METHODS: Five freshly unfrozen human cadaveric specimens were used. Arteries and veins were marked and bilateral classical lingual flaps (extending from the second premolar to the retromolar area) were prepared. In one side, the mylohyoid muscle was detached to increase the coronal extension of the flap. An implant drill was used to measure the extension of the flap after exerting 30 g of traction, before and after detaching the mylohyoid muscle. The size of the largest vascular structures of the flap was measured using a periodontal probe. RESULTS: The classical flap extension was 5.99 mm (95% confidence interval (CI): 5.08 to 6.90), while the coronally advanced flap extension with mylohyoid muscle detachment was 14.96 mm (95%CI: 10.81 - 19.11). A statistically significant difference was found between the 2 groups (p= 0.0002), with a mean extension difference was 8.97 mm (95%CI: 5.02 to 12.91). The mean largest artery had 0.20 mm of diameter (95%CI: 0.15 - 0.26). CONCLUSIONS: The detachment of the mylohyoid muscle from the lingual flap allows to significantly increase its extension by 2.5 times. The superficial arteries found in the lingual flap have a small diameter (around 0.2mm).

Third molar surgical difficulty scales: systematic review and preoperative assessment form.

BACKGROUND: The main objective of this systematic review was to collect the pre-existing scales for assessing the difficulty of third molar extraction. The secondary objective was to design a proposal for a preoperative evaluation protocol for the difficulty of third molar extraction. MATERIAL AND METHODS: Two independent researchers conducted an electronic search in Pubmed (MEDLINE), Cochrane, and Scopus databases during March 2021. Included studies evaluated the prediction of the difficulty of surgical removal of impacted upper or lower third molars using new indices/scales or pre-existing scales with or without modifications. Articles referring to coronectomies or assessing pre-surgical difficulty using other tools were excluded. Neither language nor publication date restrictions were applied. RESULTS: Out of 242 articles, 13 prospective cohort studies were finally selected. Seven developed new indices/scales, and 6 assessed the predictive ability of some pre-existing scales. Most of the indices/scales contained radiological variables and few added any patient-related variables. We proposed a preoperative assessment protocol of the difficulty of third molar extraction to facilitate treatment planning and/or considerate referral in cases of high difficulty. This proposal used patient-related, radiological and surgical variables. CONCLUSIONS: Using a preoperative protocol to evaluate the surgical difficulty, including different patient-specific, radiological and surgical variables, could facilitate treatment planning, help clinicians prevent complications and assess the possibility of referral.

Effect of bone loss on the fracture resistance of narrow dental implants after implantoplasty. An in vitro study.

BACKGROUND: Implantoplasty (IP) involves polishing of the exposed surface of implants affected by peri-implantitis (PI). A study was made to determine whether the degree of bone loss influences the fracture resistance of implants with or without IP. MATERIAL AND METHODS: An in vitro study was carried out on 32 narrow (3.5 mm) dental implants with a rough surface and external hexagonal connection. Implantoplasty was performed in half of the implants of the sample. Both the IP and control implants were divided into two subgroups according to the amount of bone loss (3 mm or 7.5 mm). Standardized radiographic assessment of implant width was performed using specific software. The main outcome variable was the maximum compression force (Fmax) of implants when subjected to static resistance to fracture tests. Implant fractures were subsequently analyzed by scanning electron microscopy. A descriptive and bivariate analysis of the data was performed. RESULTS: Significant changes in implant width were observed after IP (p<0.05). No significant differences between IP and control implants were recorded in terms of the Fmax values in the two bone loss subgroups (3 mm: control 854.37N 195.08 vs. IP 752.12N 186.13; p=0.302, and 7.5 mm: control 548.82N 80.02 vs. IP 593.69N 111.07; p=0.370). Greater bone loss was associated to a decrease in Fmax, which proved significant for the control implants (p=0.001). Fractures were more frequently located in the platform (n=13). CONCLUSIONS: Implants with more apical bone levels appear to be more susceptible to fracture. On the other hand, IP does not seem to significantly decrease the fracture resistance of narrow (3.5 mm) platform dental implants with external hexagonal connections. The fact that most fractures occur in the platform area indicates that the latter is exposed to more mechanical stress.

Erythritol-enriched powder and oral biofilm regrowth on dental implants: an in vitro study.

BACKGROUND: Peri-implant mucositis and peri-implantitis are the main biological complications associated with dental implants. Since most authors agree that bacteria play a major etiological role, the main aims of this study were to determine if a formulation of erythritol and chlorhexidine applied with an air polishing system inhibits biofilm regrowth over dental implants and to compare the decontamination capacity of this therapy with that of mechanical removal by saline and gauze. MATERIAL AND METHODS: A multispecies biofilm (P. gingivalis, A. actinomycetemcomitans, F. nucleatum, A. naeslundii, V. parvula and S. oralis) was grown for 14 days on 52 dental implants in an artificial mouth. These implants were divided into three groups according to the applied treatment: 14 negative control (CON), 19 erythritol-chlorhexidine (ERY) and 19 gauze with saline (GAU) samples. Twelve dental implants from the ERY and GAU groups and 8 implants from the CON group were re-incubated for 7 additional days after treatment. The bacterial count was performed by quantitative polymerase chain reaction (qPCR) using propidium monoazide (PMA). A descriptive and bivariate analysis of the data was performed. RESULTS: The erythritol and chlorhexidine formulation significantly inhibited biofilm regrowth in comparison with the mechanical treatment (GAU), since a significant decrease in all the species was observed in the ERY group (except for Aggregatibacter actinomycetemcomitans). The antibiofilm and antibacterial capacity of the two active treatment groups (ERY and GAU) was similar for a 14 days multispecies in vitro biofilm, except for the lower count of A. naeslundii in the GAU group. CONCLUSIONS: The use of erythritol powder with chlorhexidine applied with an air polishing system reduces biofilm regrowth over dental implants when compared with mechanical removal by saline and gauze. This effect might be beneficial for patients included in peri-implant maintenance programs.

Microbiota of alveolar osteitis after permanent tooth extractions: A systematic review.

Alveolar osteitis (AO) or dry socket after dental extractions is a common postoperative complication characterized by the presence of severe pain associated with an empty socket. Although some authors consider AO to be related to an alteration of the blood clot, the underlying etiology remains unclear, and recent reports suggest that bacteria might play an important role. A systematic review was made, compiling relevant references from PubMed, the Cochrane Library, Scopus and the Web of Science databases to determine which bacteria have been identified in AO sockets after dental extractions. Papers published between 1980-2019, identifying the bacteria present in AO sockets after tooth extractions, were included. Data were displayed in tables, and a descriptive analysis was carried out. After the screening process, four papers were analyzed, comprising a total of 138 samples from 138 patients with AO. The most commonly detected bacteria were Prevotella, Fusobacterium, Parvimonas and Peptostreptococcus. Two studies also showed the microbiota of patients that developed AO after dental extractions to be apparently different from that of patients without postoperative complications. These results indicate that bacteria may play an important role in the pathogenesis of AO, though further studies are needed to confirm these findings.

Fracture resistance after implantoplasty in three implant-abutment connection designs.

BACKGROUND: To assess the effect of implantoplasty and implant-abutment design on the fracture resistance and macroscopic morphology of narrow-diameter (3.5 mm) dental implants. MATERIAL AND METHODS: Screw-shaped titanium dental implants (n = 48) were studied in vitro. Three groups (n = 16) were established, based on implant-abutment connection type: external hexagon, internal hexagon and conical. Eight implants from each group were subjected to an implantoplasty procedure; the remaining 8 implants served as controls. Implant wall thickness was recorded. All samples were subjected to a static strength test. RESULTS: The mean wall thickness reductions varied between 106.46 and 153.75 µm. The mean fracture strengths for the control and test groups were, respectively, 1211.90±89.95 N and 873.11±92.37 N in the external hexagon implants; 918.41±97.19 N and 661.29±58.03 N in the internal hexagon implants; and 1058.67±114.05 N and 747.32±90.05 N in the conical connection implants. Implant wall thickness and fracture resistance (P < 0.001) showed a positive correlation. Fracture strength was influenced by both implantoplasty (P < 0.001) and connection type (P < 0.001). CONCLUSIONS: Implantoplasty in diameter-reduced implants decreases implant wall thickness and fracture resistance, and varies depending on the implant-abutment connection. Internal hexagon and conical connection implants seem to be more prone to fracture after implantoplasty.

Which is the most suitable local anaesthetic when inferior nerve blocks are used for impacted mandibular third molar extraction? A network meta-analysis.

The aim of this study was to compare the efficacy and safety of the different local anaesthetic agents for the extraction of impacted lower third molars. A network meta-analysis was performed of all published reports of randomized controlled clinical trials assessing efficacy (anaesthetic success and absence of need for supplementary anaesthesia during the surgical procedure) and/or safety (number of adverse events) of anaesthetic agents. Three electronic databases were searched, from their earliest records up to April 2019. Additionally, the grey literature was searched to identify further potential candidates for inclusion. Anaesthesia had to be delivered by an inferior alveolar nerve block, complemented with infiltration anaesthesia of the buccal nerve. The quality of the studies was assessed using the Cochrane Collaboration tool. This study included a total of 21 trials (2021 molars) assessing the efficacy and 19 trials (1977 molars) assessing the safety of 11 anaesthetic solutions. Seven of the studies included were considered to have a high risk of bias. The most effective local anaesthetic for the extraction of impacted mandibular third molars appeared to be 4% articaine, with significant differences when compared with 2% lidocaine, 0.5% bupivacaine, and 1% ropivacaine. Lidocaine is the safest local anaesthetic, although all investigated solutions can be used safely.

Finite element analysis of narrow dental implants.

Narrow-diameter implants (NDIs) traditionally have been associated to higher rates of failure in comparison with regular-diameter implants (RDIs) and wide-diameter implants (WDIs), since they generate a more unfavorable stress distribution in peri-implant bone. However, it is well known that the load sharing effect associated with prostheses supported by multiple implants (also called splinted prostheses) affords mechanical benefits. The present study involves finite element analysis (FEA) to determine whether the risks linked to NDIs could be mitigated by the mechanical advantages afforded by the splinting concept. For this purpose, a three-dimensional (3D) model of a real maxilla was reconstructed from computed tomography (CT) images, and different implants (NDIs, RDIs and WDIs) and prostheses were created using computer-aided design (CAD) tools. Biting forces were simulated on the prostheses corresponding to three different rehabilitation solutions: single-implant restoration, three-unit bridge and all-on-four treatment. Stress distribution around the implants was calculated, and overloading in bone was quantified within peri-implant volumes enclosed by cylinders with a diameter 0.1mm greater than that of each implant. The mechanical benefits of the splinting concept were confirmed: the peri-implant overloaded volume around NDIs splinted by means of the three-unit bridge was significantly reduced in comparison with the nonsplinted condition and, most importantly, proved even smaller than that around nonsplinted implants with a larger diameter (RDIs). However, splinted NDIs supporting the all-on-four prosthesis led to the highest risk of overloading found in the study, due to the increase in compressive stress generated around the tilted implant when loading the cantilevered molar.

Influence of information concerning a computerized anesthesia system on dental anxiety: a randomized controlled clinical trial.

BACKGROUND: A single-blinded randomized controlled trial among patients requiring an upper third molar extraction was performed to evaluate the anxiety degree after receiving information or not about the functioning of The Wand system. Secondarily, perceived pain and the need of re-anesthesia were assessed. MATERIAL AND METHODS: Patients were randomly assigned to the experimental group (detailed explanation about The Wand) or control group (no specific information). Local anesthesia with The Wand consisted in a supraperiosteal infiltrative technique injection 1.6 mL at the buccal and 0.2 mL at the palatal side. Distinct questionnaires for assessing dental anxiety and 100-mm visual analog scales to assess pain were delivered. Demographic data, radiological parameters, operative time and type of intervention were also registered. A descriptive bivariate analysis by non-parametric tests to detect differences in anxiety, pain and re-anesthesia was performed by SPSS 22.0 (SPPS Inc. Chicago, USA). RESULTS: A total of 85 patients were assessed for eligibility but 17 participants were lost due to the cancellation of the visit for the surgical intervention. Finally, sixty-eight patients were included (34 participants in each group), 47 women (69.1%) and 21 men (30.9%), with an average age of 28.8 (± 9.3) years. CONCLUSIONS: Patients that received a detailed explanation of The Wand did not have a significant reduction of the anxiety degree and perceived pain during the anesthetic act compared to patients that received no information. The need of re-anesthesia was not related to the anxiety level but was significantly related to increasing operative time.

Is measurement of the gingival biotype reliable? Agreement among different assessment methods

BACKGROUND: To determine agreement among the most commonly used methods for assessing the gingival biotype. MATERIAL AND METHODS: An electronic survey was sent to a sample of dentists practicing in Spain. The question-naire was based on the evaluation of 5 cases involving different gingival biotype assessment methods. Dentists were required to classify the cases as having a "thin", "thick" or "not able to classify" biotype. Each case was as-sessed using a frontal intraoral photo of the anterior teeth; an enlarged photo of the buccal aspect of the tooth with a periodontal probe inserted inside the sulcus; and the real thickness measured in mm with a calibrated needle. Agreement among the classifications was assessed using Cohen's kappa coefficient. RESULTS: A total of 104 surveys were analyzed. The most commonly used assessment method was visual evaluation of the morphology of the gingiva and the teeth (62.5%). Concordance among the three different methods was weak (kappa = 0.278). Agreement among the classification methods was greater in extreme cases (thinner and thicker gingival thickness). CONCLUSIONS: The most commonly used methods for assessing gingival biotype are not reliable. The three tested methods show poor to weak agreement, which leads to non-reliable estimation of the gingival biotype

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Is measurement of the gingival biotype reliable? Agreement among different assessment methods.

BACKGROUND: To determine agreement among the most commonly used methods for assessing the gingival biotype. MATERIAL AND METHODS: An electronic survey was sent to a sample of dentists practicing in Spain. The questionnaire was based on the evaluation of 5 cases involving different gingival biotype assessment methods. Dentists were required to classify the cases as having a "thin", "thick" or "not able to classify" biotype. Each case was assessed using a frontal intraoral photo of the anterior teeth; an enlarged photo of the buccal aspect of the tooth with a periodontal probe inserted inside the sulcus; and the real thickness measured in mm with a calibrated needle. Agreement among the classifications was assessed using Cohen's kappa coefficient. RESULTS: A total of 104 surveys were analyzed. The most commonly used assessment method was visual evaluation of the morphology of the gingiva and the teeth (62.5%). Concordance among the three different methods was weak (kappa = 0.278). Agreement among the classification methods was greater in extreme cases (thinner and thicker gingival thickness). CONCLUSIONS: The most commonly used methods for assessing gingival biotype are not reliable. The three tested methods show poor to weak agreement, which leads to non-reliable estimation of the gingival biotype.

Development and viability of biofilms grown on experimental abutments mimicking dental implants: An in vivo model.

BACKGROUND: To determine whether an experimental abutment mimicking the macro- and microstructure of a dental implant is a suitable method for recovering biofilm, and to describe the features of biofilms formed around such abutments on healthy implants. MATERIAL AND METHODS: Experimental abutments were used in 15 patients without peri-implant diseases. After 14 days' absence of dental hygiene in this area, the abutments were retrieved and analyzed through confocal laser scanning microscopy and scanning electron microscopy. The biofilm formation on the surface of the first 5 abutments was determined by a fluorescence-staining method using SYTO9 nucleic acid stain. In order to study the biofilm's coverage and vitality, 10 additional abutments were assessed using live & dead bacterial viability. Descriptive and bivariate analyses of the data were performed. RESULTS: A global plaque coverage of the abutments was observed in all cases. The submucosal area of the abutment was mostly covered with biofilm (over 21%). Moreover, significant differences between supra- and subgingival locations were detected. CONCLUSIONS: This in vivo experimental model allows detailed observation of the extensive plaque growth found on exposed experimental abutments mimicking dental implants when hygiene measures are absent. The biofilm coverage is significantly higher in the supragingival zone than in the subgingival portion.

Boosting the electrochemical oxygen reduction activity of hemoglobin on fructose@graphene-oxide nanoplatforms.

A metal-free oxygen reduction reaction (ORR) electrocatalyst with outstanding performance was obtained through an easy and one-pot synthesis of hemoglobin functionalized fructose@graphene-oxide (GO) nanocomposites. The active pyridinic nitrogen sites of the highly unfolded proteins together with the excellent electronic properties of GO appears to be the main factors causing the improved electrocatalytic activity.